Digital battery tester freezing liquid hydrometer is used to measure the proportion of ethylene glycol and propylene glycol with two car-based cooling system and window cleaning solution in the freezing temperature, it can check your battery electrolyte and the use of state. Freezing water cooling system calibrated in degrees Celsius. Zero calibration: 20 ° C with distilled water at 20 ° C calibration environment. Measuring Scale Model No. Measurement Range Resolution Accuracy DR601 Instrument Cleaner glass of water freezing S01 (0) -? (- 40) ℃ ?? 0.1 ℃ ± 0.5 ℃ Ethylene Glycol freezing S02 (0) -? (- 50) ℃? ??? 0.1 ℃ ± 0.5 ℃ Propylene Glycol freezing S03 (0) - (- 50) ℃ ?? 0.1 ℃ ± 0.5 ℃ Battery battery fluid proportion S04 1.000-1.500sg 0.001 ± 0.005sg??